Figure E-2. Port Diversity Example #2 – Three-Switch Setup - Comtech EF Data CDD-880 Installation And Operation Manual

CDD-880 Multi Receiver Router
Appendix E
The Virtual Router Redundancy Protocol (VRRP) eliminates the single point of
failure inherent in the static default routed environment.
A switch running STP/RSTP may take longer than 30 seconds to allow a port to forward traffic.
Ports connected to the CDD-880 should be designated as Edge Ports, or use Portfast if using a
Cisco switch, to minimize downtime during a switch. Figure E-2 shows a three-switch setup
example, where Links L1, L2, L4, and L5 are Edge Ports.
Figure E-2. Port Diversity Example #2 – Three-Switch Setup
Once the switches are configured to run STP/RSTP, a Root switch is elected, and Port Diversity is
enabled; both the Data Traffic (GE DATA) and Management Traffic (GE MGMT) IP Addresses of
the CDD-880 will be multi-homed to the chosen path's interface.
or changed, the CDD880 will issue Gratuitous ARP for both subnets to update the ARP/MAC
tables of local network elements.
configured IP Address.
Using this setup, Switch #3 has the lowest priority (Root); Switch #1's priority is a higher number
than Switch #3, but lower than Switch #2. Alternately, the same setup is achievable by setting
the path cost to the Root lower on Switch #1 than on Switch #2. This setup responds to changes
in Links L4 and L5. For example, if Link L4 is down, the CDD-880 will switch to Link L2, as the path
to the Root is better.
Figure E-3. Port Diversity Example #3 – Two-Switch Setup
The CDD-880 HTTP Interface is accessible from either
E–3
MN-CDD880
Revision 2
When a physical path is chosen